hand holding a cigarette

The Centers for Disease Control and Prevention (CDC) estimates that around 40 million American adults smoke cigarettes. If you’re one of them, you probably already know that your habit isn’t good for your health. But did you know that, according to the CDC, smoking is the leading cause of preventable disability, disease, and death in the United States?

Cigarettes are more than just tobacco and nicotine. According to the American Lung Association (ALA), cigarettes contain more than 7,000 chemicals, at least 69 of which cause cancer. Many of the chemicals in cigarettes are also found in products you’d never consider putting in your mouth. These include acetone (found in nail polish remover), benzene (found in gasoline), hexamine (also in lighter fluid), and naphthalene (an ingredient in mothballs). Cigarettes also contain hazardous heavy metals such as arsenic, cadmium, and lead.

The ALA pointed out that while consumer products like rat poison and household cleaners carry warnings about these same chemicals, cigarette warning labels don’t mention the fact that cigarettes also contain these dangerous substances. (If they did, the warning label might be too long to fit on the pack.) Quitting isn’t easy, but facing the reality of exactly how smoking is affecting your health is an important first step.

Your blood pressure may go through the roof if you smoke every day

hand grabbing cigarette from a pack

High blood pressure (hypertension) is a major health problem in the United States. According to the Centers for Disease Control and Prevention, approximately 45% of Americans have hypertension, defined as a systolic blood pressure of 130 mmHg or greater or a diastolic blood pressure of 80 mmHg or greater. Having high blood pressure greatly increases your risk for both heart disease and stroke.

According to a study conducted on mice in 2020 by researchers at Louisiana State University Health New Orleans and reported on by Science Daily, nicotine inhalation can raise blood pressure. And you don’t have to be a longtime smoker to feel the effects; both systolic and diastolic blood pressure can begin to climb after just one week of smoking. In addition to raising pressure within the body’s general circulation, smoking also increases the blood pressure within the lungs (pulmonary hypertension). The researchers noted that pulmonary hypertension was "accompanied by changes in the size, shape, and function (remodeling) of the blood vessels in the lung and the right lower chamber of the heart."

Smoking every day could throw your cholesterol out of whack

The Centers for Disease Control and Prevention (CDC) estimates that 93 million American adults have a total cholesterol level higher than 200 mg/dL, putting them at increased risk for heart disease. In addition, more than 18% of Americans have high-density lipoprotein (HDL, or "good") cholesterol levels less than 40 mg/dL. While an unhealthy diet and lack of physical activity are often at the root of individuals’ bad cholesterol numbers, smoking can also play a big role.

According to a paper published in 2013 in the Journal of Cellular Biochemistry, "cigarette smoking … appears to disrupt lipid and lipoprotein metabolism; smokers have elevated plasma cholesterol, triglycerides and LDL-c, and lower HDL-c levels as compared to non-smokers." In other words, smoking raises the harmful forms of cholesterol (LDL and triglycerides) and lowers the protective form (HDL). The authors noted that smoking’s effects on HDL were particularly dangerous. Not only does smoking reduce the amount of HDL in the blood, it also appears to change this "good" cholesterol into a substance that may actually harm artery walls rather than protect them.

Your circulation suffers when you smoke every day

If your hands and feet are always cold, your nicotine habit may be to blame. As a 2016 study published in the journal Trends in Cardiovascular Medicine explained, "Nicotine constricts blood vessels, including those in the skin and coronary blood vessels [the vessels providing oxygen to the heart], but dilates blood vessels in skeletal muscle." Reduced blood flow to the skin can cause fingers and toes to feel cold. Nicotine’s ability to constrict the smallest of blood vessels can lead to problems much more serious than numb digits. Over time, nicotine’s vasoconstrictive effects may lead to kidney disease, macular degeneration, and issues with the placenta during pregnancy.

According to Cooper University Health Care, other serious circulation-related dangers of smoking include " heart attack, stroke, aneurysm, peripheral arterial disease (PAD), limb loss, erectile dysfunction or even death." Even young smokers aren’t immune to these complications. Buerger’s disease (thromboangiitis obliterans), for instance, can affect smokers in their 20s and can lead to limb amputation. In this condition, blood vessels (usually in the arms or legs) swell, preventing proper blood flow. This in turn causes blood clots, pain, and the death of healthy tissue. While the link between smoking and Buerger’s disease isn’t fully understood, experts believe the chemicals in cigarettes may irritate and inflame the lining of blood vessels (via the Centers for Disease Control and Prevention).

Smoking every day increases your risk for cardiovascular disease

Smoking is a major risk factor for cardiovascular disease (CVD). According to the Centers for Disease Control and Prevention, heart disease kills more than 800,000 Americans annually and is the leading cause of death. Smoking causes approximately a quarter of CVD deaths. The toxic chemicals in cigarette smoke cause blood vessels to become swollen and inflamed, constricting blood flow. This can lead to atherosclerosis, a condition in which arteries narrow and harden as plaques build up along the vessels’ walls.

Eventually, this buildup can cause a blockage, leading to a heart attack or stroke. Even those who only smoke a few cigarettes a day or who choose low-tar options are putting their cardiovascular health at risk. The CDC noted that "the risk of CVD increases with the number of cigarettes smoked per day, and when smoking continues for many years."

In addition to being clearly linked to major forms of heart disease such as heart attack and stroke, smoking increases the risk for other, less common, forms of CVD. The Food and Drug Administration noted that cigarette use heightens the risk for peripheral artery disease (in which clogged arteries prevent adequate blood flow to the limbs) and abdominal aortic aneurism (in which the wall of the aorta bulges and, if it ruptures, can lead to sudden death).

You deprive your body of the oxygen it needs when you smoke every day

Every cell in your body needs oxygen to function, so having enough oxygen circulating in your blood is critical for good health. WebMD noted that smokers often have low blood oxygen levels. This is because the carbon monoxide in cigarettes physically crowds out oxygen in your blood. Certain oxygen-hungry body systems, such as your brain and your muscles, are particularly damaged by this lack of oxygen.

Carbon monoxide levels in nonsmokers range between 0 and 8 parts per million (ppm), but pack-a-day smokers have values around 20 ppm and those who smoke two packs a day may have values as high as 40 ppm. The exact amount of carbon monoxide in a smoker’s system depends on a number of factors besides how many cigarettes they smoke, including time of day and how the smoke is inhaled. In addition to being deadly at high enough concentrations, chronic exposure to carbon monoxide can increase your risk of heart disease (via carbonmonoxidekills.com).

Blood oxygen level is most often measured with a pulse oximeter, a device that clips onto your finger. According to Healthline, normal oxygen levels range between 95 to 100%. Smokers, however, may get artificially high readings because the pulse oximeter can’t tell the difference between oxygen and carbon monoxide in the blood. So don’t be lulled into a false sense of security if you smoke but your blood oxygen levels appear normal.

Smoking every day dulls and damages your senses

You may not realize it, but smoking every day is likely dulling your senses of smell and taste. According to Raleigh Capitol Ear, Nose and Throat, "Smokers are six times more likely to have poor smell than non-smokers." The chemicals in cigarette smoke damage the nerves that convey information from the nose to the brain. And, like most of smoking’s negative effects, the more cigarettes you smoke each day, the more your sense of smell will be affected.

Your sense of smell and taste are closely interconnected, so it’s no surprise that smoking can also dull your sense of taste. In fact, in an interview with WebMD, researcher Pavlidis Pavlos noted that smoking can change both the shape of your taste buds and how they function. Smokers’ taste buds tend to be flatter and have poorer vascularization (blood flow) than nonsmokers’ taste buds.

Smoking also puts your vision in danger by increasing your risk for a number of eye diseases. Smokers are three to four times more likely than nonsmokers to develop age-related macular degeneration. They also have triple the risk for cataracts and double the risk for dry eye syndrome. Likewise, glaucoma and diabetic retinopathy are more prevalent among smokers (via New York State Department of Health).

Your skin pays the price when you smoke every day

According to Verywell Mind, the toxic chemicals in cigarettes damage collagen and elastin, the proteins that give skin its structure and suppleness. This can lead to signs of premature aging (including wrinkles and sagging), especially in places where the skin is thin, like the face, neck, and hands.

The poor circulation nicotine causes can lead to impaired wound healing, leaving you with lingering scabs and scars. It can also cause spider veins and inflamed blood vessels near the surface of the skin. Smoking aggravates psoriasis and gives the skin an uneven tone because of poor oxygenation. It also increases your risk for a type of skin cancer called squamous cell carcinoma by as much as 52%. Plus, smoking is a risk factor for an inflammatory skin disease known as hidradenitis suppurativa, in which painful, pus-filled nodules form deep in the skin.

If you still struggle with acne well into adulthood, your smoking habit may be to blame. According to a 2009 study published in Dermato-endocrinology, 56% of smokers had adult acne, while slightly less than 10% of nonsmokers had pimples. Among smokers with acne, approximately two-thirds had atypical post-adolescent acne (APAA), a predominantly inflammatory condition usually found on the jaw, cheeks, and neck. The researchers argued that severe cases of APAA could be considered a unique form of "smoker’s acne."

Smoking every day will kill your sex life

People don’t like to talk about it, but sexual dysfunction is actually very common. According to the Cleveland Clinic, 43% of women and 31% of men have some degree of sexual difficulty. Sexual dysfunction can take many forms and have many underlying physical or psychological causes, but it’s often accompanied by declines in overall health.

Despite what cigarette ads may want you to believe, there’s nothing sexy about smoking. In addition to being a habit that many people consider a big turn-off, the chemicals in cigarette smoke can have a big effect "down there" for both sexes. For men, smoking can cause erectile dysfunction in guys as young as 20. That’s because the chemicals in cigarettes cause a buildup of plaques on artery walls, including the arteries that supply blood to the penis. As the plaques accumulate, blood flow is restricted and it becomes much more difficult to achieve and maintain an erection (via the Truth Initiative). For the ladies, nicotine reduces physiological sexual arousal in the genitals by about 30%, according to a 2008 study published in the Journal of Sexual Medicine.

Your mood and mental health suffer when you smoke every day

Smokers may say that they feel calmer when they light up, but cigarettes actually cause the stress and anxiety they seem to relieve. According to Britain’s National Health Service (NHS), nicotine cravings cause feelings of tension and irritability that are temporarily appeased with a cigarette, but it’s the habit of smoking that created these feelings in the first place.

The NHS also noted that smokers are more likely than nonsmokers to be diagnosed with depression, and smokers with mental health issues tend to smoke more and need higher doses of antidepressants, antipsychotics, and other medications. Nicotine triggers the release of the feel-good neurotransmitter dopamine, which is why individuals with depression find temporary relief from their symptoms when smoking. Over time, however, a smoker’s brain becomes less able to make dopamine on its own, lowering the overall amount of dopamine in the brain and encouraging smokers to smoke more (via Mental Health Foundation).

If you decide to quit smoking (and you really should), you should know that nicotine withdrawal is no joke. Be prepared for some nasty — but temporary — psychological symptoms, including anxiety, depression, irritability, and brain fog. These problems will resolve as your body readjusts to life without nicotine (via WebMD). It’s a small price to pay for a lifetime of better mental health.

Smoking every day stresses your immune system

Considering the thousands of toxic chemicals found in cigarettes, it’s no surprise that smoking can be a burden for your immune system. An immune system weakened by smoking is less efficient and less able to protect the body from bacterial and viral infections, free radical damage to cells, and cancer. Smoking also contributes to and worsens autoimmune conditions such as rheumatoid arthritis and Crohn’s disease. Autoimmune diseases arise when the immune system becomes confused and begins attacking healthy tissue (via Centers for Disease Control and Prevention).

As the authors of a 2017 paper published in Oncotarget explained, smoking hampers the "good" parts of the immune system — the processes by which it defends against invading pathogens — while simultaneously revving up the "bad" parts — processes like inflammation that, if not kept in check, can cause more harm than good. The chemicals in cigarettes negatively impact both the innate immune system (the collection of general defenses we’re born with) and our adaptive immune system (the part of our immune system that "remembers" germs we’ve encountered in the past). Some of the most significantly affected immune cells include T cells, B cells, and macrophages.

You could lose weight if you smoke, but there’s a catch

According to a 2008 paper published in The American Journal of Clinical Nutrition, smokers tend to have a lower BMI than nonsmokers. There are several possible reasons for this. Nicotine is a stimulant and, in the short term, increases your metabolic rate. A single cigarette raises energy expenditure by 3% in the half-hour after it’s smoked. Nicotine also suppresses appetite, so smokers may eat less often and consume fewer calories. On the other hand, heavy smokers (those who smoke more than two packs a day) have a higher BMI than light smokers or nonsmokers. This may not be the result of the cigarettes directly, but rather the increased likelihood that heavy smokers also engage in other behaviors that promote weight gain (such as eating a poor diet or not getting enough exercise).

While light-to-moderate smokers may see a lower number than nonsmokers when they step on the scale, that doesn’t mean their body composition is worth bragging about. Smokers tend to have a larger waist circumference than nonsmokers, which indicates they have more visceral fat. Visceral fat is stored within the abdomen and has been linked to a variety of health conditions, including type 2 diabetes. Smoking increases the stress hormone cortisol, while also lowering estrogen in women and testosterone in men. All of these hormonal imbalances are associated with higher levels of visceral fat.

Will smoking help with certain gynecological issues?

According to a landmark paper published in the British Medical Bulletin in 1996, cigarettes have an "anti-estrogenic" effect in women, meaning that they mimic the effects of estrogen deficiency. This might suggest that smoking may actually reduce the likelihood of certain gynecological issues that are caused or exacerbated by high estrogen levels, but the paper’s author was quick to point out the fact that the data often doesn’t bear this out. In the case of dysmenorrhea (painful periods), for instance, one study found that smokers had less dysmenorrhea than nonsmokers, but subsequent studies either found no connection between the two or concluded that smokers actually had higher rates of dysmenorrhea. The experts also can’t agree on whether or not smoking increases or decreases the risk of fibrocystic breast disease and breast cancer.

Heavy smokers have about half the risk of nonsmokers when it comes to uterine fibroids (noncancerous tumors in the uterus). Endometriosis (growth of the uterine lining outside the uterus) has also been shown to be less likely among smokers. According to the paper, "endometrial cancer is the only malignancy that has repeatedly been shown to be inversely related to cigarette smoking." This is particularly true among postmenopausal women.

While these "benefits" of nicotine are of interest to researchers and may warrant future study, it’s definitely not a compelling reason to continue smoking or pick up the habit.

Can smoking every day reduce your risk for Parkinson’s disease?

You may have heard that smoking could prevent Parkinson’s disease, but don’t take that as a green light to continue smoking. As the American Parkinson Disease Association explained, yes, smokers are less likely than nonsmokers to get Parkinson’s, but the exact relationship between the two is unclear. It may be that a chemical in cigarette smoke offers protection against the mechanisms that cause Parkinson’s.

On the other hand, people with Parkinson’s might simply be less likely to smoke because of how the condition affects the brain. Individuals with Parkinson’s experience a drop in dopamine levels, so smoking may not be as pleasurable or addicting. While experts are still trying to figure out how smoking and Parkinson’s are related, they agree that the numerous well-documented negative health effects of cigarettes vastly outweigh any Parkinson’s-related benefit.

Parkinson’s disease is a neurodegenerative disorder in which nerve cells in the brain break down. This causes movement problems, such as tremors, rigid muscles, balance issues, and slowed movement. Over time, people diagnosed with Parkinson’s may experience cognitive impairment, mood changes, difficulty chewing and swallowing, and sleep disturbances (via the Mayo Clinic). There is currently no cure for Parkinson’s, and it’s the 14th leading cause of death in the United States (via the Centers for Disease Control and Prevention).

When it comes to your health, vaping isn’t a great alternative to smoking

If you think you can dodge all the negative health effects of smoking by vaping instead, think again. It’s true that e-cigarettes expose you to fewer chemicals than traditional cigarettes, but they still contain a number of potentially harmful substances. E-cigarettes contain nicotine (which is heated to produce an aerosol) and are just as addictive as regular cigarettes. Vaping may also cause lung injury and even death. In fact, at least 60 deaths have been linked to vaping (via Johns Hopkins Medicine).

The Centers for Disease Control and Prevention notes that, in addition to nicotine, e-cigarettes may contain ultrafine particles that can work their way deep into the lungs, flavorings (some of which have been linked to lung disease), volatile organic compounds, and heavy metals such as nickel, tin, and lead. Because e-cigarettes are relatively new, there isn’t a lot of research on their long-term health effects. While they may assist some individuals who want to quit smoking, they haven’t been approved by the Food and Drug Administration (FDA) as a smoking cessation tool.

The bottom line: Vaping may be a somewhat less harmful option compared to smoking cigarettes, but it still comes with plenty of health risks.